The present invention relates to an improved drive mechanism for an asphalt plant used in the production of asphalt. More specifically, to an insulated drum and rubber tire drive system for use with a rotating drum.
Numerous systems for the production of asphalt are currently available today. Typically these systems use a large drum to dry and mix asphalt ingredients. The drum is normally slanted and heated with a propane burner. Raw materials enter on the high end of the drum and while in the drum the raw materials are dried by the propane burner and mixed by the turning motion of the drum.
Due to the heat created by the burners the shell of the drum may exceed temperatures of 300 degrees Fahrenheit. These high operating temperatures severely limit the types and life span of drive systems used. Further the high temperatures materially contribute to the wear on the drum drive system.
In the past drums have been gear driven or attached to a chain drive. Today the drums are often driven by steel trunnions. These trunnions hold the drum in place and drive the drum. In the trunnion systems the drum is supplied with a track or annular rail. The trunnions engage this track or rail and hold the drum in place while turning it.
As the drums are slanted and create a high amount of heat the wear on the trunnions and rail systems is substantial. This wear results in frequent replacement and repair of the trunnions and rail system. This type of system is not only expensive and time consuming to repair but is often made of specialty parts which may not be easily obtained in the event of a sudden breakdown.
From the foregoing discussion it can be seen that it would desirable to have a drive system made of common parts which may be obtained locally in the event of a breakdown. It is also desirable to create a drive system which may relatively inexpensive to repair and replace with a minimum amount of down time.
The present invention addresses these problems by providing a portable asphalt plant which uses a rubber tire drive system to run the drum. These tires are protected from the heat created in the drum by a ceramic ring around the outside of the drum. The tires are typically a multiple ply heavy load industrial tire which is readily available in most areas. The present invention also offers other advantages over the prior art and solves problem associated therewith.